First! As best friends are wont to do, Gigi Hadid memorialized Kendall Jenner's 21st birthday with an adorable pic of the pair shared via Instagram on Wednesday, November 2. Only problem? Jenner's birthday is actually November 3.

Of course, the early post may not have been a mistake on Hadid's part. The blonde stunner — who, it was just confirmed, will be returning to the Victoria's Secret Fashion Show runway — may have just jumped the gun to secure her spot as the first person to wish Jenner a happy birthday. Plus, as a source tells Us Weekly, Jenner scheduled her birthday bash for Wednesday night, making Hadid's early announcement all the more fitting.

No matter what, we're guessing Jenner won't mind. The girls have been best friends for quite some time, sharing everything from lunch to magazine covers together, including W's artsy November 2016 issue. They even have a "lover's lock" attached to the Pont des Arts bridge in Paris — a sign of true best friendship.

And if you think being in the same industry can get in the way of their friendship, think again. "I think friendships are a lot more valuable than one job," Hadid previously said of sharing the same career as Jenner. "If you’re going to let it ruin that, then that’s stupid."